This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | -16 |
| 3 | -65 |
| 4 | -55 |
| 5 | 807 |
| 6 | 4809 |
| 7 | 13135 |
| 8 | 550 |
| 9 | -169070 |
| 10 | -862710 |
| 11 | -2281174 |
| 12 | -1221309 |
| 13 | 20194565 |
| 14 | 114391575 |
| 15 | 346400092 |
| 16 | 486546751 |
| 17 | -1239516671 |
| 18 | -11089537215 |
| 19 | -41702958960 |
| 20 | -93143227027 |
| 21 | -45337210750 |
| 22 | 674845109986 |
| 23 | 3682196642725 |
| 24 | 11405949184465 |
| 25 | 20796945542222 |